a) Field of the Invention
This invention relates to a new or improved locking mechanism for chairs and to a chair incorporating such locking mechanism. The invention is particularly although not exclusively useful with rocking and gliding arm chairs.
b) Description of the Prior Art
Numerous chair mechanisms have been proposed over the years for providing a rocking motion or a rocking and gliding motion of the chair seat, and frequently such chairs include mechanisms for locking the chair seat in a desired position relative to the chair base. Mostly these mechanisms are of considerable complexity, see for example U.S. Pat. No. 5,527,095 Marshall et al and U.S. Pat. No. 3,904,240 Rogers et al. A relatively simple locking mechanism is shown in U.S. Pat. No. 3,836,532 Caldemeyer wherein an upstanding rod pivoted to the base has serrations in its rear edge which are engageable with a pin mounted in a bracket that is affixed to the chair seat portion. A cam that is operated by a lever at the side of the seat can be swung into a position to hold the serrated rod in engagement with the pin. However this mechanism is relatively flimsy and it is doubtful that it could provide adequate resistance to the high disengagement forces which could be imposed upon the locking mechanism.
The aim of the present invention is to provide an improved locking mechanism is through a comparatively simple structure provides a strong and reliable locking action, and furthermore is convenient and easy for the occupant of the chair to utilize.